Hydraulically operated clutch



Aug. 25; 1942.

L. F. G. BUTLER EIAL 2,293,967 HYDRAULICALLY-OPERATED CLUTCH Filed May 20, 1940 4 Sheets -Sheet' 1 zffinderufaoi L. F. e. BUTLER ETAL 2,293,967 HYDRAULICALLY-OPERATED CLUTCH Filed May 20, 1940 4 Sheets-Sheet 2 Aug. 25, 1942- L. F. e. BUTLER ETIAL 2,293,967

HYDRAULI CALLYOPERATED CLUTCH Filed May 20, 1940 4 Sheets-Sheet 3 w Z1 6. 3 5 Z/TEAM' M Aug 25, 1942.

L. F, G. BUTLER ET AL HYDRAULICALLY-OPERATED CLUTCH 4 Sheets-Sheet 4 Filed May 20, 1940 JrwcutorS a? g mrdiffi Bu E Z? Vaai rwwd Patented Aug. 25, 1942 2,293,967 HYDRAULICALLY OPERATED CLUTCH Leonard Frederick George Butler and Harry Thomas Underwood, Bristol, England, assignors to The Bristol Aeroplane Company Limited, Bristol, England, a British company Application May 20, 1940, Serial No. 336,303

In Great 2 Claims.

This invention relates to hydraulically-operated clutches of the kind in which the hydraulic liquid is subjected to rotation within the clutchmechanism. It is found that the resulting centrifugal force causes the separation of fine solid particles (herein termed sludge) from the liquid the accumulation of which sludge within the clutch tends to interfere with the proper working of the mechanism; The sludge is too fine to be removed by an ordinary filtering process and the invention therefore provides, in combination with a clutch of the kind described, a centrifugal separator (herein termed a centrifuge) separate from the clutch but driven in company therewith, and means for supplying to the clutchmechanism only liquid which has passed through the centrifuge. The centrifuge is preferably gear-driven by a rotating clutch-part to which the liquid is admitted so that the centrifuge is operated whenever the said part is rotating.

A specific embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which:

Figure 1 is a sectional rear elevation through the volute casing of a supercharged radial-cylinder internal-combustion engine, in which the supercharging blower is driven through gearing including a hydraulically actuated friction clutch,

Figure 2 is a sectional elevation of one of the (centrifuges of Figure 1,

Figure 3 is a section on the line 33 of Figure 2, and

Figure 4 is a plan, being a section on the line .'44 of Figure 3 but arranged in the same man- ;ner as the corresponding parts of Figure 2.

Figure 5 is a horizontal sectional view taken on the line 5-5 of Figure 1.

Figure 6 is a transverse sectional view taken ;along the line 66 of Figures 1 and 2.

As shown in Figure 1, the impeller-shaft 23 @carries a pinion 22 which is engaged by a gear 2| carried by the rotatable casing 26 of a hydrauliecally-actuated friction clutch such as that de- -scribed in British Patent No. 465,612. The casing and teeth 2| are rotated by the driven member of the clutch, the driving member of the clutch being driven by a pinion (not shown) on .a shaft 36. The pinion meshes with a gear carried by the engine crank-shaft. The clutchmechanism described in the specification above referred to forms a change-speed gear whereby the impeller-shaft 23 can be driven either at one speed or at another in relation to the engine shaft. However, the present invention can be applied to any hydraulically-actuated clutch in which the hydraulic liquid is subjected to rotation within the clutch-mechanism, and is not limited to a two-speed system.

The casing 25 is formed With facings 26, 21, which receive, spigoted into them, bearmg-cra- Britain August 11, 1939 dles 28, 29, for two oil centrifuges, denoted gen-.

erally in Figure 1 by the numerals 30 and 3| Each centrifuge carries a gear 32, 33, respectively, meshing with the gear 2| on the clutch-housing 20. Each centrifuge is constructed in the manner which will now be described with reference to Figures 2, 3 and 4. The cradle 28 is integrally formed with forward and rearward brackets 31, 38, respectively, which carry a fixed hollow spindle 39 in bushes 40, 4|, the spindle being locked against movement by a suitable bolt 42 in the bracket 31.

The spindle is hollow except for a central partition 43 so as to provide two central conduits 44 and 45 for oil. The conduit 44 is penetrated by a radial port I9 which registers with a suitable hole 46 in the bush 40 and with a conduit 41 passing through the interior of the bracket 31. The base of the cradle 28 is formed with a rib 48 the interior of which is drilled to form a transverse conduit 49 which communicates with the conduit 4'! by way of an enlargement 50. At a suitable angle to the conduit 49 it is penetrated by a conduit 52 which (see Figures 1 and 6) opens into an enlarged recess 5| in the cradle 28, the recess registering with a recess 53 in the casing 25. Oil from the lubrication system of the engine is fed to a union 54 from which a conduit 55 leads to the recess 53 above referred to. A similar conduit 56 leads by way of co-operating recesses 5'! (in the housing 25) and 58 (in the cradle 29), to a conduit 59 from which the oil is fed to the forward end of the hollow spindle 60 of the centrifuge 3I. In Figure 1 the cradle of the centrifuge 3i is shown in section and the cradle 30 in elevation. The centrifuges are identically similar in construction.

The conduit 45 in the rear end of the spindle 39 communicates through a radial port I8, and a hole 6I in the bush 4 I with a conduit 62 formed in the bracket 38. The conduit opens into an enlargement 63 with which a transverse conduit 64 communicates As shown in Figures 1 and 6, the conduit 64 leads to a recess 65 which registers with a recess 66 in the casing 25 and from this recess a conduit 61 leads to a clutch-controlling valve .which is shown in Figure 5 of the drawings at I69 and which may be similar to the valve I69 shown in Figure 1 of British Patent No. 465,612.

As more fully described in the British Patent No. 465,612, oil passes from the sump or other source through such valve I96 to one side of the clutch while oil from the other side of the clutch passes through the valve I60 back to the sump or other source of supply. Where more than one centrifuge is employed, a corresponding number of valves may be used or all may connect with the same valve. In the present invention, oil passirig from the sump to the valve I66 for use in the clutch must first pass through one of the oil centrifuges via union 54 and one of the conduits 55 or 56. When leaving the centrifuge 30, the cleaned oil passes through conduit 61 to valve I and then to the clutch. Oil forced out of the clutch returns through the valve I00 to the sump.

In Figure 5 is shown a sectional view looking down upon the top of the clutch 2|. Two valves I00 are shown, one for each of the centrifuges employed. As indicated by the arrows, oil is pass ing from each valve I00 through conduits 8 5 to the spindle 36 of clutch 20 to move the clutch in one direction. This operation forces oil from the other side of the clutch out through conduits H to the valves I00 from whence it is returned to the sump of the engine lubrication system. When the clutch is to be operated in the opposite direction, oil passes through conduit II to the clutch and from the clutch through conduit 85 to the valves and back to the sump. The direction in which the oil travels is controlled by the valves I00.

'Conduits and recesses similar to 64, 65, 66 and 61 are also provided for the centrifuge 3 I.

The spindle 39 'is surrounded by a hollow shaft 68 with which a central circular diaphragm 69 and the gear-teeth 32, already referred to, are integrally formed. The shaft 68 isseparated from the centrifuge by bushes 10, ll, of bearing'metal to which the shaft is secured. The shaft S8 is surrounded by the innermost walls 14, 15, of two open-ended cylinders 15, 11, the open ends abutting against the diaphragm 6S and the cylinders being held together by nuts I2, 13, engaging the tubular shaft 58. Each cylinder 16,11, is integrally formed with eight radial vanes or webs, the vanes in'the cylinder 16 being denoted by the numerals 18 to 85. 'Only seven of the vanes, numbered 05 to 92,of the cylinder "IT can be seen in thedra'wings, it being sufficient to state that the two cylinders and their vanes are identically similar, each being an image of the other in the plane of the diaphragm 09;

The arrangement of the various ports in the spindle, shaft and Vanes'will now be 'eXplain'ed with reference to the flow ofoil through the cen trifuge. The oil enters the union 54; flows along the conduits55, 49, 51; into the central conduit 44 in the spindle 39; From this conduit the oil flows through ports 93 and 94 in the spindle 39 to an internal groove 95 in the bush H. The bush is formed with ports 93, 91, registering with ports 98, 99, respect'vely in the shaft 68 and with ports IOI, I02, in the central tubular portion of the cylinder 11. The oil flowing through the port IOI enters the space between the vanes 88 andSS. In this space as in all the other spaces between the vanes, the oil is subjected to centrifugal force whereby fine particles of sludge'separate'from' the pure oil and are deposited on the inside of the outer wall of the cylinder 11. The partition 88 is formed at its left-hand end (see Figures 2 and 4) with a port I93 through which the oil flows into the space between the vanes 81, 88. The vane 8'! is formed at its right-hand end with a port I04 through which the oil leaves this compartment and enters the compartment between the vanes 80 and 81. From this compartment the oil flows through a hole I05 in the diaphragm 60 into the compartment between the vanes 18 and 85 in the cylinder 16. At the lefthand end (see Figure 4) of the vane I8 it is formed with a hole I05 through which the oil flows into the space between the vanes I8 and 19. At the right-hand end of the vane 19 it is formed hole H3 in the vane 89,

with a port I01 through which the oil flows into the space between the vanes 19 and 80. From this space the oil flows radially inwards through a port I08 in the central cylindrical portion 14 of the cylinder 16, a port I09 in the shaft 68, a groove H0 in the bush I0 and ports III and H2 in the spindle 39, into the central conduit 45 at the rear end of the spindle. From this point the cleaned oil' flows by way of the ports I8 and GI, the conduits 62,04, and 61, to the control-valve of the hydraulic clutch.

Half of the oil which enter the compartments 88, 89, through the port IflI will follow the path above described. The other half flows through a a hole H4 in the vane 90, a hole H5 in the diaphragm 69, a hol H6 in the vane 8|, a hole H1 in the vane to the port I08, where the two streams of oil reunite. In like manner the oil which flows through the port IE2 into the compartment at the bottom of the cylinder 11 flows to and fro through the compartments to the holes I05 and H5 and the oil which flows from these holes to the port I08 splits into two paths one of which ha already been described and the other of which is identically similar but takes place through the compartments between the vanes 85,04; 82, 83 and '83, 84, to the port II8 from which it flows to the port I I2 in the interior of the spindle.

It will be seen from the arrows in Figures 2, 3 and 4 that from one end of the centrifuge to the other the oil follows a long zig-zag path during which it is continuously subjected to centrifugal force whereby the sludge is separated from it.

The centrifuge 3I acts in the same manner, the cleaned oil from both centrifuges flowing to the control-valve.

The gears 32 and 33 by which the centrifuges are driven are conveniently of smaller diameter than the gear 2! so that the centrifuges are driven at a high speed.

It will'be seen that th invention ensures that, whenever the clutch-housing 2| is rotating, the centrifuges operate to remove sludge from the oil supplied to it. In this way, obstruction to the free movement of the piston, clutch-member, and other parts Within th housing 20 i prevented.

' We claim:

1.'The combination with a hydraulically-operated clutch of the kind in which the hydraulic liquid is subjected to rotation within the clutch mechanism of a centrifugeseparate from the clutch and gear-driven by a rotating clutch part to which liquid'is admitted, and means for supplying to the said centrifuge only liquid which is to be passed to the clutch mechanism.

2. In an internal combustion engine, the combination with the liquid pressure lubricating system thereof, of a hydraulically operatedclutch of the type in which the hydraulic' liquid is sub: jected to rotation within the clutch mechanism, said clutch having a 'rotatabledriving element and a driven element, a centrifuging liquid cleaner operatively connected to the driven element of said clutch to be operated thereby, means to convey liquid under pressure from the engine lubricating system to the centrifuging cleaner and from the cleanerto the clutch mechanism, and means to return the; liquid from the clutch to the engine lubricating system.

LEONARD FREDERICK GEORGE BUTLER.

HARRY THOMAS UNDERWOOD. 

